Livingstone was the first directly-elected mayor of London following the establishment of the post in 2000. He left Labour to run successfully as in independent in 2000 and then rejoined the party to win again in 2004.

It was his second stint at the helm in London. He had been leader of the Greater London council during the 1980s until the position was abolished by his staunch political opponent Margaret Thatcher.

Both in the 1980s and 2000s Livingstone's intense personalisation of the post was a huge electoral asset – Kate Bush even wrote a comic song about him – until a candidate emerged whose personal appeal was evidently greater than his own: Boris Johnson.

During his eight years in power Livingstone's most high profile and radical policy was introducing a congestion charge for vehicles entering the city centre. (An extension to the original charging zone was abolished by Johnson when he took over after the 2008 election.) Livingstone oversaw a modernisation of the transport system, especially the bus network, and introduced the Oyster pre-pay travelcard. A two-tier payment system evolved, with fares for those using Oyster kept relatively low while cash fares increased hugely, in a move which targeted tourists instead of locals and pushed more people into the arms of the quicker Oyster system.

Livingstone espoused multiculturalism, anti-racism and environmentalism, although he took an untypically moderate attitude towards the City during his two terms as mayor. His reputation for controversy – something he shares with his successor – reached a low point when he criticised a Jewish London Evening Standard reporter for working for a paper whose then-owners supported fascism in the 1930s by comparing him to a "German war criminal". He was given a four-week suspension from office, although this was quashed by the high court. There was more controversy when Livingstone left City Hall and was criticised for having changed the rules so that eight political advisers forced to step down when Johnson took over received an average of £200,000 in severance payments.

This habit of causing controversy has continued into the current campaign. Livingstone was criticised for describing the Tory party as being "riddled" with gay people, although a spokesperson said he didn't mean it it pejoratively. The next day Livingstone said a gay banker would "get his penis cut off in Dubai" and a week later he suggested solving the financial crisis by hanging a banker a week "until the others improve".

Last week the Jewish Chronicle published a letter a number of Labour-supporting Jewish Londoners had written to Ed Miliband to share their concerns about Livingstone. In the letter they wrote that at a private meeting Livingstone had said "he did not expect the Jewish community to vote Labour as votes for the left are inversely proportional to wealth levels, and suggested that as the Jewish community is rich, we simply wouldn't vote for him". Asked whether he made the comments, Livingstone replied: "Absolutely not." The Guardian's Jonathan Freedland, who was at the meeting, said that Livingstone did make this point, though he did not use the exact words suggested in the letter. The letter also said Livingstone used the words Zionist, Jewish and Israeli interchangeably "in a pejorative manner".

So far Livingstone has made the major theme of his campaign the rising cost of living in the capital. Earlier this month he made six key policy pledges:• To cut transport fares by 7% this year and freeze them throughout 2013.

• To reverse Johnson's police cuts and restore local sergeants.

• To help reduce rents and improve homes with an all-London non-profit lettings agency.

• To tackle heating bills through insulation and an energy co-operative.

• To introduce a London education maintenance allowance of up to £30 a week.

• And to introduce support for childcare with grants of up to £700 for low-income families and interest-free loans.

That YouGov poll mentioned above seemed to show Johnson pulling ahead. In a two-horse race, respondents backed Boris over Ken by 54% to 46%, an eight-point lead for the Conservative. The equivalent figures for last month were Boris 51%, Ken 49%.

Post your questions for the former – and perhaps future – mayor in the comments below.

10am:Please keep your questions for Ken Livingstone coming below.

In the meantime this blog will also be following news from the campaign.

Photograph: Ian Nicholson/PA

In what he partly sees as an answer to seemingly constant disputes with tube unions, Boris Johnson (left) has promised today to introduce "the first driverless trains" on the London Underground within a decade.

Trains already run without drivers on the Docklands Light Railway routes in east and south-east London.

The Conservative mayor also promised to lobby the government to change strike laws to mandate a minimum turnout in strike ballots.

And he said there would be 600 of his new Routemaster buses on the streets by the end of his second term. The mayor has been criticised because only eight are so far in service.

I want a new mandate from Londoners to automate the tube network - to improve journeys, cut delays, drive down costs and keep fares low.

Over the next four years I will no longer buy a tube train with an old-fashioned driver's cab. By 2014 we will have capacity for automatic trains on 48% of the network - and now is the time to take that programme further.

It is time for London to learn from other metro networks and get the benefits of automatic train control. It is time to move forward with "train captains" - along the lines of the DLR - with all the efficiency benefits at will bring, and absolutely no loss of safety.

With automatic trains, we will be able to expand and improve the service - and that will be good for London Underground employees as well as for passengers.

Under my leadership, TfL will rapidly establish a timetable for introducing the first driverless trains to become operational on the London Underground network within a decade ...

It may be that some hardline union barons will object, as they have traditionally objected to many technological improvements. But I am convinced that most members of London Underground's workforce will see the merit of what we are doing.

We have already begun the process of explaining the plan to staff - and once certain myths are exploded the response is positive. And I am requesting a mandate from Londoners to push again for changes to national strike law, so that industrial action can no longer be triggered by a small minority of union members.

He also warned today that further expansion of Heathrow would be "an environmental disaster " and made clear his ongoing opposition to the idea of a third runway at Heathrow, insisting that "it will not be built as long as I am mayor". Hélène Mulholland has the full story here.

Johnson says the driverless trains will not be "unmanned". A "staff member" will always be on board "to assist customers as they do on the DLR".

Johnson says "automatic train control" will be introduced on 48% of London Underground trains by the end of 2014, with the first driverless train "within a decade".

The lines he is talking about are the Jubilee, Central, Northern, and Victoria lines.

He says that automatic train control "allows trains to run closer together at higher overall speeds, increasing capacity".

Driverless trains will "over time, make the system cheaper to run and cheaper to use".

He adds: "It will also reduce the bargaining power of the union bosses intent on bringing London to a halt."

The minimum turnout he is talking about for strike ballots is 50%.

It's interesting that he frames the choice facing Londoners in a very similar way to that in which Labour nationally frames the choice between Ed Miliband's party and the Conservatives. Johnson's transport manifesto reads:

The choice at this election is between investment in our transport system - or cuts in investment at the worst possible time.

He is referring to Ken Livingstone's proposed 7% cut in transport fares. Livingstone says he can save the money without damaging investment.

These are the areas of south London he is going to "explore" extending the cycle hire scheme to: Bromley, Croydon, Hounslow, Kingston, Richmond and Romford.

He also promises to construct a new tunnel from Greenwich to Silvertown and "examine the feasibility" of a new pedestrian bridge between Vauxhall and Chelsea bridges.

And he says the 600 new Routemasters will not cost any more than "an existing hybrid bus".

An RMT spokesman said the poster falsely portrayed Crow and the RMT as part of a "corrupt, venal, scandalous and wasteful group of cronies" around Livingstone, and also as supporters of the Labour candidate.

Crow, the spokesman said, was not supporting Livingstone's campaign, and was not a member of the Labour party, and the RMT was not affiliated to the party.

Londoners could be forgiven for believing that a "driverless" Tube train will be one from which any trace of the RMT and ASLEF will be instantly purged, thereby liberating the capital from strike action for all time. In reality, the advent of trains that don't have human beings with a union cards sitting in cabs at the front end will also be the advent of trains that have human beings with union cards moving around inside the carriages making sure the doors are working, checking Oyster cards and so on.

In other words, "drivers" might be on the way out as part of a wider move towards increasing automation of the system - the substance of Boris's pledge on this is that the Northern Line upgrade will increase it from the current 30% to 48% - but "train captains" will be on the way in and they will be just as free as "drivers" to be in the RMT or ASLEF and take industrial action. Boris's manifesto contains no aspiration at all to prevent "train captains" from joining unions.

In his speech, Boris explained that they would do the same job as the staff who work on the Docklands Light Railway. The RMT told me recently that the vast majority of these DLR staff are its members. They've also shown that they are willing to go on strike. Boris's manifesto says that "moving to automation on this scale...will reduce the bargaining power of the union bosses," but when I asked him to explain why this would be so, he told me he he'd be disappointed if the unions opposed the changes he has in mind - a perfectly good answer to a question I hadn't asked.

Will unionised "train captains" replacing unionised train "drivers" on one London Underground line by the end of 2014 mean fewer strikes? Sources at Transport for London have explained to me that the change would probably make it easier for management to lessen the impact of strike action, because it is easier to train replacements in the skills required to fill in for a train captain. But it was emphasised that's not the main reason for extending automatic train control technology. The real point is that enables trains to run closer together, which means increased frequency and passenger capacity.

Serious question: what is your biggest regret from your first eight years as mayor? What should you have done that you didn't quite manage? And good luck, a Londoner as mayor of London. Should be mandatory.

I regret not getting on to climate change more quickly. I wish the government's devolution of powers over housing had occurred earlier – that's not a regret as such but it certainly is something I would have liked to be able to do more on and could not. I would like to have found a way to involve the Lib Dems more in my second term and if I can I will aim to address that this time round, if they are willing.

The fares cut I am offering is the biggest policy in this campaign. It has set an agenda others have to follow and I will carry it out, at no cost to the investment programme. We need it. Londoners want it.

My fares pledge in the past was to freeze fares in real terms, meaning that they would not rise by more than inflation. In fact what happened was that they fell in real terms on the tube and very substantially on buses, which have more travellers than the tube. This is shown in this official data from Transport for London (fig. 8.6).

If I can make a broader point, I don't think there is a single other politician in Britain more associated with cutting fares and reducing the cost of transport, from the development and expansion of the Freedom Pass in the 70s and 80s, to the Fares Fair cut, to the abolition of bus and tram fares for everyone under 18 in full-time education, student discounts, the freeze on fares in my first term, and now my plan for a Fare Deal fares cut.

And if you really don't believe me after all of that, the commitment is totally crystal clear. If I haven't cut the fares on or by October 7 this year I will quit the mayor's office and precipitate a byelection.

Some lettings agents are ripping off Londoners with 11% finders' fees every time a property is let, which means they also have an interest in constantly churning the tenants. Some unscrupulous agencies rip people off with all sorts of charges. The non-proft lettings agency will cut out the profits of these lettings agents to help landlords who want to take part, and so lower rents. This is a lettings agency that works for Londoners, not for profit. We do need more affordable houses in London - only 56 were built in the last six months - and I will work to change that.

Whilst fares, rents, energy bills and the cost of childcare all rising that doesn't mean "there's no money left" as we are constantly told. It means that transport companies, some landlords and lettings agents, big energy companies and others are all taking more money out of the pockets and purses of ordinary Londoners. They have more money. My policies will give Londoners back more of their own money.

I'll make your day, Harry. One, I will resign if I don't carry out the fares cut on or by October 7. You can't say fairer than that. It's a cast iron commitment. Two, if you look at my record as mayor it's one of massive delivery – congestion charging, successfully bidding to host the Olympics, revival of the bus service, free bus and tram travel for kids, licensing of mini-cabs, go ahead for Crossrail. It is on a different scale to the present Tory mayor and shows I'm motivated by getting things done, not spin and presentation.

4.31pm: Livingstone is racing through these questions. elliebesley asked:

guardian.co.uk

Having read Boris's manifesto and been thoroughly let down, can you assure the voters that you will have more to offer the 42% who do not have access to a car? Will you be able to outline budgets and priorities for walking, cycling, public realm, speed reductions and so on?

I agree with that, Ellie. As London's population is going to grow by a million in the next decade we need a big expansion of bike, bus, DLR and tram travel to bridge the gap before we build Crossrail 2 and 3. Boris Johnson made "smoothing the traffic flow" his priority for roads - I will put cyclist and pedestrian safety back into the equation.

What I care most about is crime in the capital. As a young person, I know the pernicious effects of gangs on our streets. Now, while you may claim to have put more police on the streets, it is a fact, backed up by surveys, that people in the capital felt less safe during your time as mayor. What are you going to do to curb gang violence, and end the numerous stabbings that plague east London. Please say why you think it will curb it too since more police for example, will not improve the mindset of the people in gangs and therefore will not penetrate the core of the problem.

I will restore the cuts to police numbers in London. Boris Johnson has admitted to cutting 1,700 police in London, even at a time when some serious crimes are rising. I will restore police numbers and beef up the teams that can intervene in gang and knife crime, including in schools. I'm going to set out some more detailed policy on crime, including crime against young people, gangs and so on, soon. One thing that is completely clear is that the Tory candidate has utterly failed. He made knife crime against young people an absolutely central issue in the last campaign. Since then it's gone up. It is a scandal that disgraces his office, a broken promise connected to broken lives. I won't make promises I won't keep but I will work with young Londoners to try to find a solution where the Tories have failed. Too many people's lives are affected.

On the NHS I believe the government is heading to full privatisation. If people in London are angry about it, they should join up to my campaign and help me fight it.

On the riots sentencing, given Boris brags about spending a night in the cells after the Bullingdon club trashed a restaurant, but was then released without charge, it does seem like there's one law for Eton boys and another for everybody else.

London's people and the tolerance of its citizens are what makes London such a great city.

My aim is to make cycling much easier and accessible across London. I promised the cycle superhighways – but they have been botched by the Tory mayor and in many cases are downright dangerous. I will get them reconfigured so that they are much safer for cyclists. My full manifesto will talk in more detail about this.

What do you propose to do with regard to relations with the tube unions? For many Londoners it has reached the point now where we want driverless trains, as the unions are constantly striking and making ridiculous demands (claiming that safety is an issue yet they always end up asking for more money, as if a higher salary for tube drivers increases safety!). Boris has said he will introduce driverless trains. What is your strategy for dealing with the unions?

All trains will need staff, otherwise there will be no one to cope with breakdowns, technical faults or even to help with terrorist incidents. Driverless Underground trains are pie-in-the-sky – but in any case even without drivers the DLR has seen strikes among its staff.

In other words it doesn't solve the issue of industrial disputes, which is what seems to motivate this convoluted policy from the Tories.

Boris Johnson promised a no strike agreement with the unions. He hasn't got one because he won't even meet with them. He has never asked them to talk to him about it. It is one of the most totemic of all his failures. The result has been 23 strikes in the last four years, which is more than I had in eight years. More strikes in one term than across my period as mayor combined.

And once we had really go to grips with the tube you saw an even sharper decline in strikes than the average figures would suggest. To reduce strikes you need a mayor who will negotiate with the workforce - not grandstanding and producing chaos. During the eight years I was mayor the number of shifts on the tube lost due to strike action was cut by 98%.

Can you foresee a handover of control of all rail London and inevitably London commuter services to TfL [Transport for London] under your mayorship, and if so, what benefits will this bring to London and the south-east? And please do bring back light rail proposals like Cross River Tram!

I was negotiating this with the last Labour government when I lost the election, but Boris Johnson decided not to continue with it. I'll restart the negotiations with government. We'll start preparatory work on the Cross River Tram immediately.

Despite all the smears by Andrew Gilligan, three separate investigations (including a committee of Tory council leaders appointed by Boris, the district auditor, and a two and a half year operation by the police) all concluded there was no evidence of corruption or cronyism under my administration. Boris Johnson's co-worker at the Telegraph Andrew Gilligan is now at it again with smears suggesting I'm a tax-dodger and even more preposterously implying that I'm planning to make London a Muslim city. Gilligan wants to talk about anything but my fares cut, which will save the average Londoner £1,000 over the next four years.

Please can we be allowed to booze on public transport again? I really miss being able to share a civilised four-pack of Red Stripe on the long haul from Wimbledon into town before going on a night out.

No, of course not. That would be silly. But Barclays should be congratulated on the cheapest sponsorship deal ever. They clearly saw the mayor coming. What I intend to do is roll out cycle hire far more widely across London, so many more Londoners can benefit. But that needs a far less expensive scheme, which I will oversee as a priority.

1) According to the Channel 4 FactCheck your policy on fares would have to be paid for from the capital account of TfL and therefore would lead to less being spent on essential works such as upgrading the signalling system on the tube and on station refurbishments; Is this true?

2) According to the Channel 4 FactCheck your policy to reintroduce the EMA involves using monies that are not under the direct control of the mayor; indeed one council leader has declared that the policy is "writing a cheque on our account without asking us". Can you provide details of how this will be paid for using monies that are directly under your control?

3) Will you reverse the decision by BJ to allow motor bikes into TfL-controlled bus lanes?

On your FactCheck points we simply disagree about the policy. Last year, there was a £727m surplus on the operating budget and my fares policy costs £270m. Let's be clear about this – it's the unplanned surplus. It happens every year that there is such a surplus. That's at least in part because fares are so high, and ridership is not collapsing, so the revenue shoots up every year. That's money straight out of Londoners' pockets. Disgracefully investment has been underspent too. So of course there's money enough to cut fares without [touching] the capital budget.

On EMA, I explicitly said when I announced this that it was not mayoral money. It is money currently in schools, colleges, universities and local authorities. We have been talking to a number of the organisations and agencies involved and I am confident we can find a way to restore EMA in London.

My record is clear – I have used the mayoralty in the past to deliver things that people said I could not. That's what the mayor's office is all about. The money is there for this - and have already agreed in principle to work together to restore EMA. This is exactly the approach I took with the Freedom Pass - which is not paid for by the mayoral budget, but which I won for older Londoners so that they could travel free on the network.

On bus lanes by the time the election is over, we will have had long enough to assess whether motorcyclists in bus lanes have deterred cyclists. If they have not then there's no reason to change the scheme, but if they have we would need to review it.

Hasn't Ken learnt from the reigns of Thatcher and Blair that the longer one is in power, the more it corrupts, and that the desire to continue in power arises not from a desire to improve the lot of others but the status of oneself?

Power doesn't corrupt, it often attracts the corrupt; a love of money is what corrupts as people lust after more extravagant lifestyles. What I value most is not money but the people I love and the people I work with and what I can achieve. I have only one motivation here – I am standing for London mayor because I care about this city and I cannot stand by in such extraordinarily tough times. At a time when millions of Londoners are struggling, I do not believe enough is being done to help them. Fares are rocketing, police are being cut and now pensioners are being attacked thanks to the cut in the top rate of tax that Boris Johnson campaigned flat out to secure. My kids are growing up in this city now, and I don't want them living in a city where no one is taking action to put Londoners first. I don't want any other elected office, I'll actually cut the mayor's pay, I will work my way through the highest paid salaries in City Hall and ensure fairer pay overall. The focus will be the majority, not just a few relatively privileged Londoners.

5.05pm: Livingstone has responded to some of the accusations of antisemitism that have been made against him (see above). Silverbrow asked:

guardian.co.uk

Are all Londoners equal? If so, what is your response to the concern amongst the Jewish community arising from your attitude towards them?

I will be mayor for the whole city, as I was before. In each year I was mayor, antisemitic attacks declined and even during Israel's invasions of the Lebanon when antisemitic attacks soared in the rest of the UK and Europe, they did not rise in London. This was because all London's different communities live side by side peacefully in this city, unlike the situation in much of the rest of the world.

I am going to work with the London Jewish Forum as I did before and I am proud to be fighting alongside Jewish Labour members to make London a fairer city.

Yes, to be honest. After the prime minister using House of Commons privilege to campaign in the mayoral election on this issue, there are now more than a few questions about the most senior members of the Tory frontbench. But in my view the tax argument is a manufactured diversion, an attempt to ensure that issues that really matter to Londoners like cutting their fares or improving access to childcare are drowned out in a frenzied soap opera. In the last few days we've seen what the real tax issue in this election – a granny tax pensions raid to pay for Boris Johnson's top rate tax cut. The budget has been a sobering wake up call for anyone who thinks that the election is about the soap opera the Tory campaign wants to see.

Graphic

5.10pm: That's it from Ken Livingstone. Many thanks to him for getting through so many questions.

The key points were:

•Responding to Boris Johnson's plans to introduce driverless trains on the London Underground (officially announced today), Livingstone said that the non-driving staff who would work on these trains would still be able to strike. "In other words it doesn't solve the issue of industrial disputes, which is what seems to motivate this convoluted policy from the Tories."

•To concerns about his attitude to Jewish people, he said that he was "going to work with the London Jewish Forum as I did before and I am proud to be fighting alongside Jewish Labour members to make London a fairer city". Antisemitic attacks declined during his time in office, he said.

•And he defended his policy of cutting transport fares by 7%, saying there would be more than enough surplus money to cover it "without [touching] the capital budget". The issue has become a key faultline between Livingstone and Johnson – leading to Johnson's position seeming to shift today when he said he would "hold fares down", giving no further detail.